Plaintiffs challenged the construction of a bridge to be built across the Potomac River at the Three Sisters Islands near the Georgetown Historic District in Washington, D.C., an area listed in the National Register of Historic Places. They asserted that the Department of Transportation (DOT) had not complied with Section 15(a) of the Federal-Aid Highway Act and that the decision to go ahead with the project was the result of undue political pressure. Members of Congress had threatened the agency with a cutoff of funds if the project did not proceed.

The court held that under Section 15(a), before the project could begin, DOT must determine that all possible planning had been done to minimize harm to the affected historic district. Because the final design for the bridge had not been completed, it was premature for DOT to assert that it had complied with Section 15(a). The expectation that future planning would result in minimal harm to the historic area was not sufficient. Moreover, DOT erred by failing to consult with other planning agencies to coordinate efforts to minimize harm to the historic district. 459 F.2d at 1239.

The court also found that DOT's determinations were invalid because they had been made as a result of undue political pressure from members of Congress who had clearly threatened the agency with fiscal reprisals if it did not approve the bridge project. Id. at 1245. In enacting the Federal-Aid Highway Act, Congress did not intend for the agency to consider such threats in reaching decisions on bridge projects. Id. at 1247.

The court remanded the case to the district court, directing it to enjoin construction until DOT could comply with Section 15(a). Id. at 1249. The court also asked the litigants to submit supplemental briefs on the applicability of the National Historic Preservation Act (NHPA) and other statutes. After these had been received, the court issued a supplemental opinion, concluding that DOT must comply with Section 106 of NHPA and afford the Advisory Council on Historic Preservation an opportunity to comment before final approval of the project. 459 F.2d at 1265.